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0will be unjustified pricing, lowering quality, choosing not the most worthy ones.
Thus, the new model carries a number of contradictions that can lead to disruption of the reform. Do not throw it away. One needs to carefully examine all possible flaws and propose measures to correct a number of model provisions.
References
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2. Зaкон y^ai™ № 4456 "Про оргaнiзaцiю ме-дичного обслyговyвaння нaселення в Укрaïнi" вiд 15 квггня 2016 р.
3. Проект Зaконy Укрaïни № 2409a "Про зaсaди держaвноï полiтики охорони здоров'я" вщ 17 липня 2015 р.
4. Дaвидович I.G. Медико-соцiaльнi aспекти проблеми здоров'я нaселення Укрaïни // Новости медицины и фaрмaции. - 2007. - № 19 (227). - С. 2930.
5. ^ршишев Д.В. Концепщя iнновaцiйниx пе-ретворень: мiжгaлyзевий пiдxiд до реформyвaння системи охорони здоров' я (держaвно-yпрaвлiнськi aспекти): Моногрaфiя. - Х.: Вид-во ХaрРI НАДУ "Мaгiстр", 2004. - 304 с. Бiблiогр.: 135 нaзв.
ВЛИЯНИЕ 6-БАП НА СОДЕРЖАНИЕ ГИББЕРЕЛЛИНА А3 В СОЦВЕТИЯХ TRADESCANTIA (CLON 02) ПРИ ОБЛУЧЕНИИ В МАЛЫХ ДОЗАХ
Хомиченко А.А.
кандидат биологических наук, ведущий инженер, Институт биологии Коми научного центра
Уральского отделения РАН Скоробогатова И.В.
кандидат биологических наук, старший научный сотрудник, РГАУ-МСХА им. Тимирязева
6-BENSYL-AMINO-PURINE IMPACT ON TRADESCANTIA (CLON 02) INFLORESCENCE GIBBERELLIN A3 CONTENT UPON LOW-DOSE Г-IRRADIATION
Khomichenko A.A.
PhD in Biological sciences, leading engineer Institute of Biology of Komi Scientific Centre of the Russian Academy of Sciences
Skorobogatova I. V.
PhD in Biological sciences, Senior Researcher Russian State Agrarian University - Moscow Timiryazev Agricultural Academy of the Russian Academy of
Sciences
Аннотация
Было изучено влияние пролонгированного у-облучения на соцветия Tradescantia (clon 02), обработанные 6-бензиламинопурином (БАП-6). Содержание гибберелловой кислоты в модельных растениях показывало рост как в абсолютных, так и относительных значениях. Мы предположили, что обработка растение БАП-6 препятствует адекватным ответам растений на ионизирующую радиацию. На основе результатов, представленных в данной работе, нами было сделано предположение, что гиббереллин A3 обеспечивает позитивную регуляцию механизмов активного восстановления радиоиндуцированных генетических повреждений.
Abstract
Prolonged y-irradiation in Tradescantia (clon 02) inflorescences treated with 6-bensyl-amino-purine (BAP) was studied. Gibberellic acid content in the model plants was shown to increase both in absolute and relative values in the series of variants. We suggested that the treatment of the plants with 6-BAP hinders an adequate plant response to ionising irradiation. On the basis of the findings obtained in the present work we suggested that gib-berellic acid can regulate positively the mechanisms ensuring active radio-induced genetic damage recovery.
Ключевые слова: цитокинины, гибберелловая кислота, гиббереллин, у-радиация, малые дозы, Tradescantia (clon 02), розовые мутации, 6-бензиламинопурин, 6-БАП, генетические нарушения, генетические повреждения
Keywords: cytokinins, gibberellic acid, gibberellin, y-irradiation, low doses, Tradescantia (clon 02), pink mutations, 6-bensyl-amino-pirine, 6-BAP, genetic lesion, genetic damage.
Results and discussion. Up to date many mechanisms which control cell cycle were discoveres, cyto-kinins are known to be involved in governing of these memachanisms. This hormone also ensures connection between them and the mechanisms responsible for DNA damage recognition. Another aspect of this hormone's influencing the cell cycle is its participating in
the replication processes (Suchomelova et al., 2003; Larkins et al., 2001; Riou-Khamlichi et al., 1999; Dahl et al., 1995; Soni et al., 1995; Houssa et al., 1994; Fransic D., 2007). This allows to refer cytokinins to the key factor ensuring genetics structure stability under a genotoxic stress, particularly upon low-dose y-irradiation.
Gibberellic acid regulates a series of processes essential in plant response to low-dose ionising irradiation. This makes the problem of their interaction under genotoxic stress very interesting. Studying of the interaction of cytokinins and gibberellins can give us deeper insight into the role of gibberellic acid in the low-dose effects due to the character of cytokinins' involvement in the responses to such factors as y-irradiation which are studied properly and the results of exposure are predictable enough.
We designed the experiment on Tradescantia (clon 02) plants treated with synthetic 6-BAP cytokinin dwelling in the conditions of prolonged y-irradiation. We tried to estimate the interaction of these hormones through determining the gibberellin A3 level in the irradiated Tradescantia inflorescences.
Materials and methods. Gibberellin A3 content was determined in Tradescantia (clon 02). Plant stem cuttings having flower inflorescences with 2 or 3 inter-nodes were used as the starting raw material. All of the inflorescences were obtained during spring-summer period. Prior to irradiation the cuttings with inflorescences where placed into distilled water, 17 hours later the inflorescences were irradiated with 226Ra. The irradiation dose varied due to the irradiation intensity changing, the exposure time was 20 h, maximum irradiation dose - 9.0 cGy. During the irradiation the plants were submerged into the 6-BAP solution (10 -3mol/L). Immediately after having been irradiated, the inflores-
40
cences were cut off, weighed and fixed in a water-etha-nol mixture (80:20 by volume). The fixation time for each sample was 1 hour. Gibberellic acid content was evaluated by the biological method. Estimation of A3 gibberellin biological activity was performed through applying to Frankland and Wareing method (Frankland, Wareing, 1960). Berlin(sky) lettuce variety (Holland selection) was used. Gibberellins content was assessed on the calibration curve, for its plotting gibber-ellic acid produced at Russia.
A series of works showed the Tradescantia (clon 02) responses to the definite dose range irradiation to be qualitatively different from each other. Earlier we conducted an experiment on cytokinins content in the inflorescences irradiated with low doses (Homichenko A. A. et al., 2007).
Irradiation in the overall dose range i.e. from 1.0 up to 28.0 cGy brought about significant reduction of the hormons' content, dropping to the minimal level upon 2.3 cGy dose irradiation. The experiment with the provoking irradiation indicates that Tradescantia (clon 02) inflorescenses tissue radio-resistance increasing upon irradiation with 2.3 and 4.86 cGy doses () . Fig. 1 presents the findings on the gibberellic acid assessment upon the irradiation with doses up to 9.0 cGy. These data is indicated for one of the levels of the irradiation existing in the range of 2 - 3 cGy, which is essential character in radio-biological processes. Thus, the irradiation in the abovementioned dose range results in the radiobiological effect manifested in different indices.
35
30
25
20 15 10 5 0
1 I
I I I
I
I
control 0,4 cGy 1 cGy 2 cGy 3 cGy 4 cGy 5 cGy 7 cGy 8 cGy 9 cGy
Fig. 1. Gibberellic acid content in the Tradescantia (clon 02) inflorescences upon irradiation with up to 9.0 cGy doses. Abscissa - dose; Ordinate - GA A3 level (ng/g of raw weight).
We faced the question, working with the plot obtained above: is the cytokinins' level reduction a prerequisite for the effect induction?
In order to answer this question the experiment on irradiated Tradescantia (clon 02) inflorescences treatment with a synthetic 6-benzylaminopurin (cytokinin) was performed. The level of gibberellic acid was chosen as the marker exhibiting the Tradescantia (clon 02)
inflorescences tissues transition from normal state to post-irradiated one.
The statistically significant increase of gibberellic acid from 20.61+0.47 ng/g (T-test, p<0,05) of raw weight to 67.74+2.94 ng/g is the first interesting finding on the impact of 6-BAP on Tradescantia (clon 02) inflorescences (Fig. 1 and 2). This effect may be ac-
counted for by the total/general increase of the cell metabolism upon the exogenic cytokinins impact. Other types of interrelation between these two hormone levels are possible as well.
6-BAP impact does not affect the pathway direction of the hormonal system response to irradiation with the dose range from 0.4 up to 2.0 cGy. Similarly to the plants which were not treated with 6-benzylminopurine the gibberellin content increased, it enhanced with respect to the untreated plants both in absolute and relative values. The gibberellin content increased 1.59- fold in plants not treated with 6-BAP, having increased from
200
20.61+0.47 ng/g of raw weight up to 32.73+2.98 ng/g. The plants treated with synthetic cytokinin and irradiated with the above doses exhibited the increase from 67.74+2.94 ng/g of raw weight up to 168.56+6.28 ng/g, with A3 gibberellin content having been increased 2.9 fold. Upon the inflorescences being irradiated, gibber-ellin level lowered 5.14 fold. This indicates that the gib-berellin's level change manifestation being an essential radio-biologic effect upon irradiation in doses 2 - 3 cGy, with these plants having not been treated with 6-BAP.
180 160 140 120 100 80 60 40 20 0
J*
J?
I
I
X X
X*
X*
\
a
Fig. 2. Gibberellic acid content in the Tradescantia inflorescences upon 6-BAP treatment in the control and upon irradiation with up to 9.0 cGy doses. Abscissa — dose; Ordinate —GA A3 level (ng/g of raw weight).
Interestingly, the gibberellic acid content in 6-BAP treated inflorescences for the variants with irradiation from 3.0 up to 9.0 сGy also exhibited its being increased with respect to the control both in absolute values for the variants with doses 3.0, 5.0 and 9.0 сGy and in the relative values of 4.0 and 7.0 cGy respectively, with the level of gibberellic acid varying significantly in the range from 32.79+1.09 mk/g of raw weight to 86.79+5.66 mk/g of raw weight (p<0.05, T-test). The value of each variant was statistically different (p<0.05, T-test) from that of the previous one. In the
inflorescences not treated with 6-BAP the level of gibberellic acid steadily declined, dropping to the minimum level upon irradiation with 9.0 cGy (Fig. 1).
Cytokinins are critical hormonal factors ensuring the genome stability in genotoxic stress conditions. The dramatic decline of this hormone content upon low-dose irradiation (Homichenko et al., 2007) is most likely to point to the general cell cycle pathway (Fig. 3). Primarily, this may be connected with the active checkpoint reaction of the cell cycle. Transient-term arrests of the cell cycle under genotoxic stress allow time to induce different repair branches and to recover the genetic damage.
600
500
400
300
200
100
control
1 cGy
2,3 cGy
4,86 cGy
9,8 cGy
28 cGy
Fig. 3. Cytokinin content in the control and upon low-dose irradiation. Abscissa - dose, cGy; Ordinate - CTK level (mkg/g of raw weight). The method precision - 30%. Note: cytokinin levels are significantly different from those of the control in all variants.
0
Cytokinins are able to increase cycline D-type level in Arabidopsis as well as that of CDKA1;1 and CDKB1;1, providing transition between all phases of the cell cycle. CycD3 sensitivity to cytokinin content is so high that it is called a cytokinin sensor. CDKs A- and B-type are directly involved in the cell cycle control (Riou-Khamlichi C. et al, 1999; Cho H.-J. et al., 2010; Pasternak T.P. et al., 2007; Orchard C.B. et al., 2005; Zhang K. et al., 2005). Cytokinin level decline results in slight CDK inhibition via activation of their inhibitors (ICK), Kip/Krp and Sim/Smr-factors (Cho H.-J. et al., 2010).
CDC25-like phosphatases found in a series of plant species are capable, as those in animal organisms of controlling cyclin-dependent kinases' activity (Landrieu I. et al., 2004; Zhang K. et al., 2005). Weel kinase, being a CDC25-phosphatase antagonist, represses the activity of the latter. Weel kinase negatively regulates CAK-kinase D-type activity as well (Shimo-tohno et al., 2006). Its level increases rapidly, enhancing profoundly in an ATM- and ATR-dependent routes under a genotoxic stress (De Schutter, K. et al., 2007). Cytokinins were shown to regulate CDC25 level positively and that of Weel - negatively (Zhang K. et al., 2005). This hormone influences the S-phase duration, activating DNA replication points (Houssa et al., 1990; 1994) and governs the S-phase checkpoints responsible for the replication start and its course (Suchomelova et al., 2004; Larkins et al., 2001).
A great number of experiments shows the 6-BAP ability to affect all aspects of the cell cycle and the cell metabolism in general. It promotes the cell cycle course
in general and that of its phases - individually, repressing the control mechanisms activity. The cells by-pass the checking points even at the presence of severe DNA damage. The impact of synthetic cytokinin results in chromatin decompactization, in promotion of the protein and nucleic acid synthesis (Polevoy V.V., 1982; Suchomelova et al., 2003; Larkins et al., 2001; Riou-Khamlichi et al., 1999; Dahl et al., 1995; Soni et al., 1995; Houssa et al., 1994; Fransic D., 2007).We suggest that Tradescantia (clon 02) inflorescences treatment with 6-benzylaminopurine is able to block the genome integrity control mechanisms and that of the cell cycle, consequently preventing the genetic lesions from repairing.
Some of the aforementioned processes are governed by both gibberellic acid and cytokinins. Particularly, gibberellin is capable of inducing the expression of cyclin A- and B-group, cyclin-dependent A-, B- and D-type kinases (Fabian T. et al., 2000; Inzé D., De Veylder L., 2006; Sauter, Kende, 1992; Sauter et al., 1995; Sauter M., 1997; Lorbiecke R. and Sauter M., 1999). y-Irradiation low-doses induce conservative mechanisms involved in the daily activity of live organisms and required for maintaining the genome integrity. Thus, particularly, one of them is connected with the activity of plant CDK7 homologs classified as CDKD. CDKD-kinases are catalytic subunits of plant CAK-complex subunits activating CDK A and B-type. The above mentioned mechanism is involved in TFIIH transcription factor and modulates the activity of the largest RNA-polymerase II subunit (Umeda et al., 2005;
Shimotohno et al., 2006), their activity being interdependent, with those being involved in different DNA damage repair branches. In actively proliferating tissues these two hormones control the concerted mechanisms aimed at rapid synthesis and duplication of the genetic material and DNA damage repair occurring in the course of normal cell activity (Sauter, Kende, 1992; Sauter et al., 1995; Sauter M., 1997; Zhang K, 1996; Umeda et al., 2005; Shimotohno et al, 2006). Under genotoxic stress conditions we observe a new situation. Cell cycle checkpoint mechanisms' responses and many other mechanisms require cytokinins level reducing being impacted by a genotoxic agent.
While the gibberellic acid content dependence in Tradescantia (clon 2) inflorescence on the dose level reflects adequately the inducing of the radio-biological effect resulted from 2.0 - 3.0 cGy irradiation, the question formulated in the beginning of the text is to be answered negatively. The effect observed in our research is not determined by cytokinin-controlled mechanisms.
The increase of gibberellic acid in the inflorescences not treated with 6-BAP under irradiation in doses from 0.4 up to 2.0 cGy is believed to be aimed at the plant cells repair potential enhancing upon the increasing dose-load. This assumption is in agreement with many findings in literature indicating gibberellic acid as a substance involved in the governing of a wide range of the repair processes. The gibberellin level increase in plants treated with 6-BAP in irradiated in doses from 0.4 up to 2.0 cGy is supposed to be related to the synthetic cytokinin's effect preventing the plant cells to form an adequate response to y-irradiation is likely to result in DNA damage, in the dose range increasing from 3.0 up to 9.0 cGy. The gibberellic acid level increase in dose range from 4.0 to 7.0 cGy might be aimed at compensating the genetic lesion multiplication through different repair processes deregulation. The subsequent reduction of the hormone levels in the dose range from 5.0 up to 9.0 cGy variants seems to be related to induction of the repair mechanism contributing to the genome restoration potential increase.
Conclusion. If we are to distinguish the cell response to the genotoxic factor according to its phases, the processes ensuring DNA damage recognition, with the cell cycle inhibition following, are to be referred to the primary ones. The processes of the DNA lesions recovery including, particularly, different repair branches activation, the repair ferments and desoxy- and ribonu-cleic acids synthesis will be referred to the secondary ones. Hormonal system of the primary responses is provided mainly through cytokinins and auxins. On the basis of the findings presented, gibberellic acid is likely to contribute to the abovementioned processes under low-dose y-irradiation conditions, ensuring the DNA structure recovery per se.
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THE IMPACT OF HEALTH SYSTEM PROBLEMS ON THE DEMOGRAPHIC SITUATION IN
UKRAINE
Chornenka Zh.A. Yasinska E. Ts. Shevchuk M.M.
Abstract
The article examines the modern health care system in Ukraine, its impact on demographic processes and problems. Over the past decade, demographic indicators in Ukraine have shown a tendency to reduce fertility, increase mortality and reduce natural growth, and our mathematical forecasting of these indicators shows the same unfavorable trend in the years to come, which will lead to a reduction in working resources in the country.
Keywords: demographic situation, birth rate, mortality, demographic factors, working age.
According to the Institute of Demography. M.V. Ptukhs ", as of January 1, 2017, the population, excluding the occupied territories, was 36 million people. The figure is significantly less than the official data of Ukr-stat - 42.6 million people. The census of population in Ukraine has not been conducted since 2001. By 2050, while maintaining the population's tendency, another 8 million people will be reduced. to 27.9 million people. And this is without taking into account the expected outflow of Ukrainian migrants after the opening of "visa-free travel". In reality, the population of Ukraine, the largest country in Europe, in 30 years may be less than 20 million people. Just think about it, 20 more years ago we had 50 million.
Obviously, the two most numerous age groups are at risk. Those who are 25-35 years old today are the most active and motivated young people. They easily find high-paying jobs abroad and go to permanent residence in Poland, Hungary, etc. The visa-free regime with the EU opens up even more opportunities for their migration.
The second group is people of pre-retirement age. In 10 years, most of them will go on a well-deserved rest, and the burden on their provision will fall on the younger generation.
The labor resource of Ukraine will be replenished by those who are now under 20 years old. Their share is the lowest in the total number of people of working
